This Is Us 's Chrissy Metz Admits She Was on 'Pins and Needles' Filming Emotional Goodbye Scene

Ron Batzdorff/NBC

This post contains spoilers for This Is Us.

The emotional farewell to Rebecca Pearson was tough for This Is Us fans to watch, but it was just as challenging for the cast to film.

During a series finale screening and panel on Sunday, Chrissy Metz opened up about shooting the scene where her character, Kate, runs to her mother Rebecca's (Mandy Moore) bedside after flying in from London.

"So many people have experienced that, and I've experienced it with family members myself, and there's nothing you can do," said Metz, 41. "You're at the mercy of a flight and everything has to go according to plan in order for you to make it."

She continued, "But the most beautiful thing is Rebecca saying she's waiting for someone and how beautifully that was portrayed, but also that wanting to get there so desperately. We're all on pins and needles. She's waiting for Kate, she's waiting for 'Bug.'"

Metz added that the moment was meaningful not only for her character, "but also [in terms of] the relationship with Mandy and I." She couldn't help but be moved by the gravity of "having to run in and hope that moment hasn't passed — and what it would mean if it did, and she didn't get to say goodbye, even though they had this amazing experience of their life together."

Ron Batzdorff/NBC Chrissy Metz as Kate and Mandy Moore as Rebecca in This Is Us

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Metz said she's "so grateful" that series creator Dan Fogelman "wrote it that she was able to say goodbye."

"It wasn't easy, y'all," she added. "Saying goodbye is one of the hardest things, because you're saying goodbye to the show but you're also saying goodbye to a character."

Moore confessed that, contrary to what she expected, Rebecca's many goodbye scenes weren't easy for her either. While listening to her costars' delivering their final words, she recalled, "I started crying with my eyes closed. I had tears streaming down my face ... so that was oddly one of the more challenging parts, having to put myself in a completely different frame of mind. I just couldn't listen, I was gonna cry all day."

Metz noted that the moment was extra poignant because, "You're also saying goodbye to a friendship as far as the six years go, so it was very layered. And of course, as this episode shows, we never truly say goodbye. It's just, 'See you later.'"

Ron Batzdorff/NBC

In the penultimate episode, the Pearson family matriarch died after battling Alzheimer's disease. Rebecca first learned of her cognitive impairment issues in the show's fourth season.

Moore, 38, said playing someone suffering from Alzheimer's disease was the "most terrifying and daunting aspect of anything having to do with the show." Because of that, she did her own research and even spoke to a neurologist to ensure she was respecting those who suffer from the condition.

"This is not part of my story, but I did recognize it is millions and millions of peoples around the country and world," she said at Sunday's event. "I felt an incredible sense of responsibility to make sure we got it right."

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This Is Us will conclude after six years on Tuesday — but Fogelman, 46, and his cast recently revealed that they shot parts of the series finale years ago. He explained at Sunday's panel that he made that choice "primarily to capture [the kids] in a moment of time when it would feel nostalgic to us and to the audience."

"We shot it at the beginning of season 3, but with the pandemic, it added time," he continued. "I never looked at it, so we shot four or five days worth of material with the kids and Milo and Mandy, and some of Sterling [K. Brown] and Ron [Cephas Jones] and Eris [Baker] and Faithe [Herman] and then we put it away and never looked at it again. And then about two months ago, I said to our editors, I was like, 'Guys, I have to look at it now. I have to know before we go any further that it's good and that it's what we want it to be.'"

Fogelman added, "For me to have built it and watched it, that was my first moment of my shoulders going down a little bit and relaxing because I saw the footage that existed that we shot 3-4 years ago, and was like, 'Ok, we have it, it's really good.' I knew that was gonna be the final shot of the episode. Lonny, watching his father watching the family, and I was like, 'Ok we have it now,' and that relaxed me."

This Is Us' series finale airs Tuesday at 9 p.m. ET on NBC.